Sunday, November 30, 2008

Dean Zimmerman's New Paper Against Molinism

Molinism -- the view that God knows not only what free creatures do, will do and could do, but also what they would (freely) do in every possible circumstance -- is a popular view among contemporary Christian philosophers. William Lane Craig uses it to account for such things as the compatibility of the inspiration of scripture and human free will, the compatibility of freedom and foreknowledge, and the compatibility of a semi-exclusivist account of soteriology with the fact that many will never hear the gospel and will be damned. And it's arguable that Alvin Plantinga requires molinism for the success of his famous free will defense against the logical problem of evil (although some, such as Swinburne, deny this. Kenneth Perszyk argues that Plantinga's free will defense is doubtful with or without molinism).

Two common criticisms of molinism (cf. R. Adams, Hasker, et al.) are that (i) it leaves the counterfactuals of human freedom without a metaphysical grounding, and that (ii) molinism involves a vicious explanatory circularity. However, "star" metaphysician and Christian philosopher Dean Zimmerman (Rutgers) has a huge (90 page) paper coming out (in a collection in honor of Robert Adams), and it offers a critique of molinism that's wholly independent of these two criticisms. It's also persuasive. If he's right, then philosophers like Craig will have to look elsewhere to solve the problems mentioned above.

Here's a link to the paper.

P.S., Dean Zimmerman is one of my favorite contemporary metaphysicians. See his stuff on material composition, David Lewis' global supervenience thesis, his stuff on the A-theory of time, and his stuff on the metaphysics of gunk (I know, funny philosophical jargon).

Nature Red In Tooth and Claw

I mentioned earlier that MIchael J. Murray was writing some books on two important problems for theism since at least the publication of Hume's Dialogues Concerning Natural Religion and A Natural History of Religion: the problem of animal suffering, and the plausibility of naturalistic accounts of religious belief. Well, I've been meaning to post on this for a while, but Michael J. Murray's book-length reply to the problem of animal suffering, Nature Red in Tooth and Claw, is now available. It came out a couple of months ago. His book on naturalistic accounts of religious belief, The Believing Primate, which is an edited collection of newly-commissioned papers, is due to come out next April.

Friday, November 28, 2008

Notes on Draper's Article on Behe's Design Argument, Part 6: Are Direct Routes Really Impossible?

In this installment, I complete the series on Draper's critique of Behe's design argument from irreducible complexity.

I. Review and Setup
To review, recall that the article focuses on stage one of Behe's two-stage design argument, which argues that certain biochemical structures couldn't have arisen via gradualistic Darwinian processes. The argument of this stage crucially relies on his notion of irreducible complexity, where this is defined as a system "composed of several well-matched, interacting parts that contribute to the basic function, wherein removal of any of the parts causes the system to effectively cease functioning".[1] With this notion in hand, Behe argues that there are irreducibly very complex biochemical systems (e.g., the bacterial flagellum), and that these systems can't plausibly be explained in terms of gradualistic evolutionary processes. And the reason is that evolution can only create systems via direct and indirect evolutionary pathways.[2] But evolution can create no irreducibly complex system via adirect evolutionary pathway.[3] And while evolution can create simple irreducibly complex systems via indirect pathways, and reducibly complex systems via direct and indirect evolutionary pathways, the odds are overwhelmingly against creating irreducibly very complex systems via indirect pathways.[4]

Given Behe's argument, there are at least three ways to criticize his argument directly:

(1) Undercut or rebut the claim that his example systems are irreducibly complex (or at least irreducibly very complex)
(2) Undercut or rebut the claim that irreducibly (very) complex systems can't be created via indirect evolutionary pathways
(3) Undercut or rebut the claim that irreducibly complex systems can't be created via direct evolutionary pathways

In previous installments, we saw that Draper has offered criticisms of type (1) and type (2). Each of these criticisms is sufficient by itself to defeat Behe's argument. However, Draper doesn't stop there. In this installment, we'll look at one of Draper's criticisms of type (3).

II. Behe's Argument Against Direct Evolutionary Pathways to Irreducible Complexity
Now as mentioned above, Behe argues that direct routes to irreducibly complex structures are impossible. But why think that? His argument can be stated as follows: consider some irreducibly complex system S composed of parts A and B, which together perform function F. Now since S is irreducibly complex, neither A nor B can perform F by itself. Therefore, if we assume that neither A nor B served some other useful function in the interim[5], then if either A or B came into existence before the other, it would've been eliminated before the second part came into being to interact with the first part to perform F. Therefore, direct routes to irreducibly complex systems are impossible.[6]

III. Draper's Reply
What to make of this argument? To set up Draper's critique, recall that Behe distinguishes between two sorts of evolutionary pathways for creating biological systems: direct and indirect. A gradualistic evolutionary pathway leading to a function F of a biological system is direct if it produces F by continuously improving it without changing F itself, and without changing the system's mechanism. And a gradualistic evolutionary pathway leading to F is indirect if it does so by changing the system's function or mechanism.[7] But as Draper points out, this account of evolutionary pathways is too coarse-grained, as it fails to distinguish different kinds of direct and indirect evolutionary pathways. And it turns out that these further distinctions have a bearing on whether Behe's argument succeeds.

Thus, to redress this shortcoming, Draper distinguishes between two sorts of direct routes to irreducible complexity: simple and complicated. A simple direct route amounts to adding parts to a system without changing the function or the mechanism. By contrast, a complicated direct route can involve both adding and subtracting parts (again, without changing the mechanism or the function).

Thus, Behe fails to distinguish between simple and complicated direct evolutionary pathways. But the problem is that Behe wrongly assumes that all direct pathways are of the simple variety. For as it turns out, it's possible for complicated direct routes to generate irreducibly complex systems. Draper states his criticism as follows:

"The possibility of an irreducibly complex system's being produced by a complicated direct path is fairly obvious. For example, an irreducibly complex two-part system AB that performs function F could evolve directly as follows. Originally, Z performs F, though perhaps not very well. (This is possible because, from the fact that AB cannot perform F without A or B, it doesn't follow that Z cannot perform F by itself.) Then A is added to Z, because it improves the function, though it is not necessary. B is also added for this reason. One now has a reducibly complex system composed of three parts, Z, A and B. Then Z drops out, leaving only A and B. And without Z, both A and B are required for the system to function."[8]

Thus, Draper shows the logical possibility of a complicated direct path to an irreducibly complex system in four stages:

Stage 1: A system S is composed of Z, which performs function F. (simple system)

Stage 2: Part A is added to Z in S, leading to an improvement in F. (reducibly complex system)

Stage 3: Part B is added to Z and A in S, leading to an improvement in F. (reducibly complex system)

Stage 4: Part Z drops out of S, and without Z, BOTH A and B are required for S to continue performing F. (irreducibly complex system)

Draper's criticism surfaces an illicit assumption implicit in Behe's reasoning about what follows from his definition of irreducible complexity: that the irreducible complexity of a system is insensitive to the parts that make it up. But as Draper's counterexample shows, this isn't so: whether a system is irreducibly complex is relative to the constituents of which it's composed. Thus, while a system S may be irreducibly complex if composed of A and B, it may well be reducibly complex if it's composed of C and D. In short, irreducible complexity is parts-relative. And this leaves open the possibility of creating an irreducibly complex system directly by (e.g.) first starting with a reducibly complex system composed of CD, then successively adding parts A and B to improve its function, and finally losing CD, resulting in an irreducibly complex system composed of AB. And given this possibility, Behe's argument against the possibility of direct routes to irreducible complexity is defeated.

IV. Conclusion
As I mentioned earlier, Draper raises a number of other criticisms of Behe's design argument from irreducible complexity, but I think enough of his criticisms have been discussed to indicate that Behe's argument is a failure. For his key clams -- that some biochemical structures are irreducibly complex; that irreducibly very complex systems can't be produced by indirect evolutionary pathways; and that irreducibly complex systems can't be produced by direct evolutionary pathways -- are defeated.
--------
[1] Behe, Michael J. Darwin's Black Box: The Biochemical Challenge to Evolution (New York: The Free Press, 1996), p. 39.
[2] Recall that a gradualistic evolutionary pathway leading to a function F of a biological system is direct if it produces F by continuously improving it without changing F itself, and without changing the system's mechanism. And a gradualistic evolutionary pathway leading to F is indirect if it does so by changing the system's function or mechanism. Draper, Paul. "Irreducible Complexity and Darwinian Gradualism: A Reply to Michael J. Behe", Faith and Philosophy 19:1 (2002), p. 5
[3] Irreducibly complex systems "cannot be produced directly, because any precursor to an irreducibly complex system that is missing even a single part is by definition nonfunctional." Darwin's Black Box, P. 39.
[4] "Even if a system is irreducibly complex (and thus cannot have been produced directly), however, one can not definitively rule out the possibility of an indirect, circuitous route. As the complexity of an interacting system increases, though, the likelihood of such an indirect route drops precipitously." Behe, Darwin's Black Box, P. 40.
[5] As many -- including Draper -- have noted (e.g., Kenneth Miller), this assumption is fatal to the argument. For from the fact that neither A nor B can perform a particular function F without other parts, it doesn't follow that neither part can perform some other funtion(s). And in fact, there are plausible evolutionary pathways where Behe's paradigm case of an irreducibly complex system -- the bacterial flagellum -- has evolutionary precursors that performed different functions. (See the following YouTube clip of a talk by Kenneth Miller for a helpful example of such a criticism.). However, that sort of criticism is one demonstrating the possibility of indirect pathways to irreducible complexity. I therefore relegate the criticism to a footnote, not because it isn't important, but because it falls outside the scope of the current topic, which focuses on direct evolutionary pathways to irreducible complexity.
[6] This statement of Behe's argument is a paraphrase of Draper's. See Draper. Irreducible Complexity and Darwinian Gradualism: A Reply to Michael J. Behe", Faith and Philosophy 19:1 (2002), p. 15.
[7] Ibid.
[8] Ibid.

Craig on the Leibnizian Cosmological Argument

Although Craig has criticized the Leibnizian Cosmological Argument in a number of places, he offers a brief defense of it in The Rationality of Theism (Routledge, 2003, ed. Paul Copan and Paul Moser).

The Leibnizian cosmological argument depends on some version of the Principle of Sufficient Reason (PSR). The standard formulation of PSR can be expressed as follows:

(PSR) There is a sufficient reason for the existence of (a) every object, and (b) every state of affairs, either in terms of something else or in terms of its own nature.

A standard criticism of the argument is that PSR(b) is false.[1] Craig states the criticism tersely: "There cannot be an explanation of why there are any contingent states of affairs at all; for if such an explanation is contingent, then it, too, must have a further explanation, whereas if it is necessary, then the states of affairs explained by it must also be necessary." (p. 114)

Craig defends the argument against the criticism by eliminating PSR(b), and just relying on PSR(a) to get the conclusion of a necessarily existing object -- God -- as the explanation of the contingent universe.

However, this won't do. For as Peter van Inwagen points out[2], the conclusion can't be gotten with just PSR(a). For suppose there is an infinite, beginningless series of dependent beings[3], such that each being is explained in terms of another, as follows:

...C --> B --> A

In this series, A is explained by B, B is explained by C, and so on. But if so, then each contingent being in the series is explained by another contingent being. And if that's right, then PSR(a) is satisfied in such a scenario, and yet there is no need to appeal to a necessary being.

Now one might say that the series of contingent beings is itself a being, and so PSR(a) isn't satisfied without appeal to a necessary being. However, things aren't so easy. For ever since Christian philosopher Peter Van Inwagen wrote Material Beings[4], it's not so clear when, or even whether, two or more things compose another thing. Enter the material constitution debate. Thus, whether the collection of dependent beings is itself a being depends on which theory of material composition is true. A universalist (or "allist"), would say that any two or more objects is itself is an object. A nihilist (or "noneist") would say that no two objects compose an object -- there are only simples and their aggregates. Everyone else falls somewhere in between (the moderates). The problem is that every position on the matter has counterintuitive implications. Therefore, at the very least, it will require either a defense of a universalist account of material constitution, or a defense of a moderate account of material composition that allows the collection of dependent beings to count as a being (it should be noted that van Inwagen's own moderate account doesn't countenance the collection of dependent beings as itself a being). Needless to say, Craig has a lot more work to do in defending the Leibnizian cosmological argument against the criticism he raises here.
----------------------
[1] See for example, Peter van Inwagen's statement of the criticism in his text, Metaphysics (Westview Press).
[2] Ibid.
[3] Of course, Craig argues against the possibility of an actually infinite series such as this in his defenses of the kalam cosmological argument. But as I've argued in other posts (see Section 1.1.2 of my index, here), these arguments for a finite past have undercutting defeaters. But Wes Morriston has stated the problems with Craig's Kalam argument better than I can.
[4] van Inwagen, Peter. Material Beings (Cornell University Press, 1995).

Tuesday, November 25, 2008

Some Past Exchanges

Victor Reppert, Steve Lovell, and I on the Leibizian cosmological argument

Alan Rhoda and I on God, abstract objects, and other issues relevant to evaluating theism

Bradley Monton

Bradly Monton is a philosopher at UC Boulder. He's also an atheist. However, and perhaps surprisingly, he argues that intelligent design is a legitimate category of explanation in the sciences (in that actions of non-human intelligent agents are detectable in principle, and that appeal to such agency is legitimate in principle in the sciences). Also, he thinks ID should be taught in schools, along side evolution. He's coming out with a book on the topic: Seeking God in Science: An Atheist Defends Intelligent Design.

Another point about Monton: he thinks the fine-tuning argument, although ultimately unpersuasive, is stronger than many philosophers think. See (perhaps) his most important paper of his on this, "God, Fine-Tuning, and the Problem of Old Evidence", British Journal for the Philosophy of Science 57 (2006), pp. 405-424.

I agree with him about virtually all of this, and I can't wait to read his book. The reason: I've read the following books and articles on the topic, as well as the standard replies (although, I confess, not the replies of the last few years), and I'm not persuaded by the the latter -- which, by the way, rarely address the specific points made:

Moreland, J.P. Christianity and the Nature of Science, 3rd printing (1992), esp. Ch. 6.

-"Creation Science and Methodological Naturalism", in Bauman, Michael, ed., Man and Creation: Perspectives on Science and Theology (1993).

-"Theistic Science and Methodological Naturalism", in Moreland, J.P., ed., The Creation Hypothesis (1994).

-"The Explanatory Relevance of Libertarian Agency as a Model of Theistic Design", in Dembski, William A., ed. Mere Creation: Science, Faith, and Intelligent Design (1998)

Meyer, Stephen C. "The Methodological Equivalence of Design and Descent", in Moreland, ed., The Creation Hypothesis (1994)

Dembski, William. (That's right, I said "Dembski" -- not all is dross in his writings) "On the Very Possibility of Intelligent Design", in Moreland, ed., The Creation Hypothesis (1994)
-"Appendix" in Dembski, Intelligent Design (1999).

Laudan, Larry. “The Demise of the Demarcation Problem,” in R. Cohen and L. Laudan, Eds., Physics, Philosophy and Psychoanalysis (Reidel, Dordrecht), pp. 111-128.

-“Science at the Bar: Causes for Concern,” Science, Technology and Human Values, 7: 16-19.

Plantinga, Alvin. See his papers on methodological naturalism, the god-of-the-gaps criticism, and his discussions of "Augustinian" vs. "Duhemian" philosophy of science

Ratzsch, Delvin Lee. Nature, Design, and Science (2001).

Reynolds, John Mark. (That's right, I said "John Mark Reynolds". Just because his political blog posts are crazy, it doesn't follow that all is dross in what he has to say). "God of the Gaps", in Dembski, ed. Mere Creation (1998).

Swinburne, Richard. The Existence of God. (haven't read the new 2004 edition) See especially his discussion of personal vs. scientific explanation


Now I don't think all these pieces are right on everything they say, but they *do* make a good prima facie case for the in-principle legitimacy for appeals to intelligence in scientific explanations -- even in terms of an invisible designer. It's not responsible to ignore these arguments if you're aware of them.

Aristotle appealed to God in his scientific explanations. Was he a moonbat for doing so? No.

Theists -- at least sensible theists -- don't appeal to God in explanation by arguing in either of the following ways:

1. I can't think of an explanation for X in terms of natural causes alone; therefore, God is the explanation of X.

2. X is too complex to be produced by natural causes alone; therefore, God is the explanation of X.

Sophisticated theists make neither a blatant appeal to ignorance (as in (1)), nor an inference from mere complexity (as in (2)); they admit that neither is sufficient to justify an appeal to a designer. Rather, they add a further requirement that *X must also have some earmark of intelligence*. Thus, their reasoning is of the following generic form:

3. (i) x can't be explained in terms of naturalistic mechanisms within a a mature science, and (ii) x bears feature F that's known to be caused by intelligent ageny; therefore, probably, x is at least partly explained in terms of intelligent agency.

Different canditates for earmark F have been proposed throughout the centuries:

(a) x has parts that work together to perform a function. (Paley)

(b) x is irreducibly complex (Behe)

(c) x has specified complexity (Geisler & Anderson, Dembski).

(d) x exhibits "counterflow" (Del Ratzch)

These are all legitimate candidates in my book. So I think there's no problem with appeals to God in science, at least in principle. The problem I have is that they all fail *in practice*. For example, with reference to (a)-(c) above: evolution can produce objects whose parts work together to perform a function; the examples of irreducible complexity have been demonstrated no to be so on further inspection (cf. Kenneth Miller's stuff), and in any case, Behe's argument has big problems, as Paul Draper has shown; and Ratzsch, Collins, and Fitelson have shown that (c) admits of counterexamples.

A caveat: I have zero interest in discussing this topic, unless you've read at least a decent chunk of the works referenced above, and you want to talk about the specific arguments of a specific author listed there (e.g. "Meyer says X in article C in your list. I think that argument doesn't work, for reason Y").


P.S., listen to Brad's podcasted interviews on the topic of ID at his blog (e.g.) here.

Monday, November 17, 2008

Two Types of Design Argument

Two Types of Design Argument:

Type I: The Classical (“Old School”) Design Argument:

-This version is an argument from analogy.
-It typically appeals to living organisms and their parts as cases of apparent design

1. Human artifacts are intelligently designed.
2. Living organisms and their parts resemble/are analogous to human artifacts (in that they both are complex and their parts that work together to perform a function).
----------------------------------------
3. Therefore, probably, living organisms and their parts are intelligently designed as well.

-Paley’s version is the most important version of the classical version of the design argument.
-However, this form of the design argument is seldom used today, due to the criticisms we’ve discussed. However, philosophers have come up with a new version of the design argument:

Type II: The Contemporary (“New School”) Design Argument:

-This version is not an argument from an analogy. Rather, it's formulated either in terms of confirmation theory or an inference to the best explanation.
-According to this version, certain features of the universe are treated as data, and then various hypotheses are offered to explain the data
-It typically appeals to non-living aspects of the universe as cases of apparent design
-The two hypotheses typically proposed are (i) intelligent design and (ii) non-intelligent, natural causes. The argument can then be expressed as follows:

Let ‘D’ denote some range of data that needs explaining. For example:

D: The universe is fine-tuned for the existence of life (i.e., there are a large number of fundamental constants of nature. The value had by each of this is independent of each of the others. Each value is just one among an extremely large range of possible values, and each constant had to be assigned the value it has or no life would have arisen in the universe.)

Let ‘H1’ and ‘H2’ denote competing hypotheses offered to explain D:

H1: The fine-tuning of the universe is due to intelligent design.
H2: The fine-tuning of the universe is due to non-intelligent factors, such as chance and necessity.

Then the argument runs as follows:

1. We’d expect D if H1 were true.
2. We wouldn’t expect D (or at least not as much) if H2 were true.
3. If we’d expect the data if H1 were true more than we would if H2 were true, then H1 is more probable than H2.
----------------------------------------------
4. Therefore, H1 is more probable than H2.

Criticisms of William Dembski's Design Inference -- By Christians

The following is a short list of articles (and chapters) critiquing Dembski's design inference. They are all written by Christian philosophers.

Del Ratzsch:
Appendix: "Dembski's Design Inference", in Nature, Design and Science. SUNY Press, 2001 (in the Philosophy and Biology Series).

Robin Collins:
“An Evaluation of William A. Dembski’s The Design Inference,” in Christian Scholar’s Review, vol. 30:3 (Spring 2001).

MIchael J. Murray:
"Natural Providence (or Design Trouble)", Faith and Philosophy 20:2 (July 2003), pp. 307-327.
-"Natural Providence: Reply to Dembski", Faith and Philosophy 23:3 (2006), pp.337-41.

Timothy McGrew:
"Toward a Rational Reconstruction of Design Inferences", Philosophia Christi 7:2 (2005), pp. 253-298.
Site Meter